@PHDTHESIS{ 2025:535764650,
 	title = {Unraveling the Semicrystalline Structure of Different Types of Starch (A, B, C and V) using X-Ray Diffraction and Structural Refinement},
 	year = {2025},
 	url = "https://tede.ufam.edu.br/handle/tede/10975",
 	abstract = "Given the widespread use of carbohydrates in the industry, the complexity of their structures, and the challenges in accurately determining the semicrystalline nature of biopolymers, particularly starches, this work proposes a comprehensive understanding of the main structural characteristics of those important material and the implications of its processing. Specifically, the focus is on analyzing the structural changes in various types of starches (A, B, C and V-type) resulting from different processing techniques, with particular emphasis on nanocrystal production and structural modification. These techniques encompass acid hydrolysis, gamma irradiation and non-thermal processes (High-Intensity Ultrasound and Cold Plasma treatments). By examining the effects of these processing techniques on starch structure, this thesis aims to provide valuable insights into the modifications and transformations at the structural level, which in turn might be useful for “tuning” starches microstructure into a specific application. To overcome these challenges and achieve a more precise and unbiased characterization of starch crystallinity, a combined approach based on X-ray diffraction (XRD) and Rietveld refinement techniques was proposed. The microstructural information derived from Rietveld refinement can be integrated with other techno-functional characterizations commonly utilized in the food industry to enhance the understanding of the potential applications of starch sources. Gamma irradiation demonstrated a reduction in the amorphous fraction, accompanied by increased crystallinity, with B-type starch showing greater structural resilience due to its higher water content. Cold plasma treatment, applied under varying operational parameters, significantly influenced the crystallinity of Ariá (Calathea allouia (Aubl.) Lindl) starch, leading to increases in crystallinity by 18% at 200 Hz, as well as reductions of the amorphous content. This study presents the first quantification of phase fractions (A- and B-type) in C-type starches from Amazonian sources such as Ariá and thorn yam (Dioscorea chondrocarpa Griseb), revealing its polymorphic complexity and the remarkable potential for structural modulation. This research has far-reaching implications beyond the immediate scope of the study, with potential impacts in multiple industries such as food, packaging, pharmaceuticals, cosmetics and other biomedical sectors. By deepening our understanding of starch's structural properties and its response to different processing methods, this research holds the potential to drive the innovation in product development, processing techniques and new technologies.",
 	publisher = {Universidade Federal do Amazonas},
 	scholl = {Programa de Pós-graduação em Física},
 	note = {Instituto de Ciências Exatas}
}